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We report a case of lung abscess associated with pulmonary strongyloidiasis which occurred in an asthmatic patient three years after migrating to Australia from Burma where strongyloidiasis is endemic. Thiabendazole was effective in eradicating the Strongyloides infection.
Bronchoalveolar lavage was performed on a patient with disseminated strongyloidiasis and 4.5 X 10(7) cells/65 ml of lavage fluid were recovered. Eighty-five percent of cells were polymorphonuclear leukocytes; 15 percent were pulmonary alveolar macrophages. Rhabditiform larvae (1 X 10(4)) were recovered in 65 ml of lavage fluid. This is the first report of bronchoalveolar lavage used in diagnosing disseminated strongyloidiasis.
Parasitological diagnosis based on the faecal examination is frequently difficult in cases of chronic, low-level S. stercoralis infection. Even when a newly developed sensitive method (an agar plate culture) is applied, it is essential to examine faecal samples repeatedly to achieve a correct diagnosis. Additionally, it is important to note that a negative result does not necessarily indicate the unequivocal absence of the infection. On the other hand, several serological tests which have recently been developed for strongyloidiasis have proven reliable when used to complement parasitological examination. We have developed two serological tests, ELISA and GPAT, to demonstrate Strongyloides infection and possible applications of the serological tests for diagnosis, mass-screening, epidemiological study and postchemotherapy evaluation of strongyloidiasis were reviewed based on our recent studies.
Cryo-microtome sections of larvae of Strongyloides stercoralis and S. ratti respectively obtained from human and rat feces cultures, were used as antigens. Fluoresceinate conjugates against human IgG were employed at the ideal titer of 10 for S. stercoralis and 100 for S. ratti. The sensitivity of the indirect immunofluorescence reaction (IIF) was 94.4% and 92.5% and the specificity 94.2% and 97.1% for the two specific larval antigens, respectively. Sera from 123 persons (54 from carriers of S. stercoralis infections and 69 from controls) were submitted to the reaction. The titers of different sera varied from 20 to 2560. There was a significant linear correlation (r = 0.85 p < or = 0.001) between the antibodies from the two species of larval antigens. We conclude that both antigens may be used in the IIF reaction for the diagnosis of human strongyloidiasis. Due to the feasibility of safe and low-cost mass production of S. ratti larvae in the laboratory with a considerable economy of conjugate, their utilization in the serum diagnosis of human strongyloidiasis is recommended.
IgE antibody response in human strongyloidiasis was evaluated by enzyme-linked immunosorbent assay (ELISA) and immunoblotting (IB) using Strongyloides ratti saline extract as heterologous antigen. A total of 50 serum samples of patients who were shedding S. stercoralis larvae in feces (group I, copropositive), 38 of patients with other intestinal parasites (group II), and 38 of subjects with negative results in three parasitologic assays (group III, copronegative) were analyzed. Levels of IgE anti-Strongyloides expressed in ELISA Index (EI) were significantly higher in patients of group I (1.32) than in group II (0.51) and group III (0.81), with positivity rates of 54%, 0%, and 10.5%, respectively. Fifteen S. ratti antigenic components were recognized in IB-IgE by sera of group I, with frequency ranging from 8% to 46%. In group II, only two antigenic bands (101, 81 kDa) were detected in a frequency of 10% and no reactivity was found in group III. Sera with EI values > 1.5 recognized five from 13 specific antigenic bands (70, 63, 61, 44, 7 kDa). It can be concluded that these five antigenic components recognized by IB-IgE using S. ratti antigen might be employed as an additional tool for improving the immunodiagnosis in human strongyloidiasis.
Cutaneous manifestations in disseminated strongyloidiasis are infrequent but should raise the suspicion for its diagnosis. We retrospectively evaluated the charts of six patients with cancer and a proven diagnosis of disseminated strongyloidiasis. All patients had received prophylaxis with albendazole before starting antineoplastic therapy, which included high-dose steroids. They presented with septic shock, acute respiratory failure and characteristic purpuric periumbilical skin lesions. Strongyloides larvae were identified in tracheal aspirates (n=5), gastric aspirates (n=4), lung (n=2) and skin biopsies (n=2). All patients died despite antihelminthic therapy and intensive care support.
We report a nephrotic syndrome patient with eosinophilia who developed ileus, epigastralgia and malabsorption due to strongyloidiasis which became symptomatic by steroid therapy. The patient was then treated with thiabendazole and recovered. A percutaneous renal biopsy revealed minimal change nephrotic syndrome. This renal injury may be brought on by severe infection of Strongyloides stercoralis. It is important to rule out strongyloidiasis prior to corticosteroid therapy to patients from eosinophilia endemic areas.
There have been some reports of disseminated Strongyloidiasis associated with immunosuppressive therapy around the endemic area. We encountered an elderly patient with Strongyloidiasis hyperinfection during corticosteroid therapy. The case was a 75-year-old man, living in Tokunoshima, Kagoshima Prefecture, who had no remarkable past history. He visited a clinic because of exertional dyspnea and edema of the lower limbs. Laboratory examination showed renal dysfunction, microscopic hematuria and proteinuria. On December 2000, he was admitted to our hospital on a suspected diagnosis of rapidly progressive glomerulonephritis. Further examinations showed normal serum creatinine, severe microscopic hematuria and proteinuria of more than 3 g per day. Although we wanted to determine a treatment based on a pathologic diagnosis, considered his age and severe kyphosis, he had 30 mg of prednisolone as an empiric treatment. Strongyloides stercoralis were identified from his sputa and stool by microscopic investigation 21 days after initiation of corticosteroid therapy. Subsequently, 6 mg of Ivermectin was given twice every two weeks. S. stercoralis were eradicated and his proteinuria improved. This case suggests that S. stercoralis could be the cause of urine abnormality.
A 58-year-old chronic alcoholism patient, who complained of epigastric discomfort, nausea, and frequent loose stool was diagnosed as strongyloidiasis accompanied by duodenal ulcer. The symptoms first appeared two years ago and aggravated during the recent 3 months, and he lost 4 kg of his body weight. Stool examination revealed rhabditoid nematode larvae, which were confirmed as those of Strongyloides stercoralis after cultivation of them to filariform larvae. At duodenoscopy, duodenal ulcer was found. The patient was treated with albendazole (200 mg, bid, for 14 days) for strongyloidiasis and with colloidal bismuth sulfate (240 mg, bid, for 6 weeks) for duodenal ulcer. After the medication, the symptoms of loose stool and epigastric discomfort were much improved and he was discharged with no clinical problems. This is an interesting case which suggests that S. stercoralis infection could be related with ulceration of the duodenal mucosa.
Cambendazole was used for the treatment of strongyloidiasis in 40 hospitalized patients, given in a single dose of 5 mg/kg body weight. According to the criteria adopted, parasitological cure was obtained in 100% of cases. Side effects were negligible, and did not require interruption of treatment. We therefore conclude that cambendazole is at present the most effective agent for the therapy of human strongyloidiasis.
Peripheral lymphocytes from 16 patients with chronic uncomplicated strongyloidiasis and 15 non-infected controls were stimulated in vitro with Strongyloides stercoralis larval antigens, other non-parasite antigens and the T cell mitogen phytohemagglutinin (PHA). In the presence of autologous plasma the patients' responses to Strongyloides antigens were similar to those of controls. When lymphocytes from nine patients were cultured in the presence of normal human serum, responses to parasite antigens were enhanced, while responses to other antigens and to PHA were unaffected. Lymphoproliferative responses to PHA were significantly lower in the patients' group than in the controls. These findings suggest that in chronic strongyloidiasis, in addition to a depression of T cell activity, factors are present in the patients' serum that inhibit parasite-specific cellular responses in vitro.
Sera from 68 patients with parasitologically proven strongyloidiasis were tested by the ELISA and IHA tests using larval antigens prepared from Strongyloides stercoralis and Strongyloides ratti. The ELISA using the S. stercoralis antigen detected the greatest number of sero-reactors (83.8%), whereas the IHA using the S. ratti antigen detected the fewest (55.9%). In addition, the S. stercoralis antigen had higher geometric mean titers than the S. ratti antigen in both the ELISA and the IHA tests. Sera from 37 presumed normal individuals also were tested by IHA and ELISA and nonspecific reactions were seen only with the IHA test. When sera from patients with parasitic infections other than strongyloidiasis were tested, the only consistent cross-reactions were with those sera from patients who had occult filariasis and acute schistosomiasis.
Since ivermectin, a mixture of 2 closely related macrocyclic lactones, has proven highly effective against animal intestinal nematodes, trials were undertaken to determine its efficacy against human intestinal nematodes. We tested 110 patients with strongyloidiasis and 90 with enterobiasis; many had other intercurrent intestinal nematode infections. Stool examinations were done before and after patients were given a single dose of oral ivermectin capsules (50, 100, 150, or 200 micrograms/kg body wt); 55 recipients of 100 or 200 micrograms/kg doses received a second identical dose the next day. Kato and saline smears, ethyl acetate concentration, modified Baermann's technique, and Harada-Mori cultures were repeated; cure was defined as complete absence of eggs and/or larvae from stools tested 30 days after dosing. Ivermectin was well tolerated. Overall cure rates at all doses 30 days after therapy averaged 88% for strongyloidiasis, 100% for ascariasis, 85% for trichuriasis, and 85% for enterobiasis. Ancylostoma duodenale and Necator americanus were little affected.
Strongyloidiasis, a human intestinal infection with Strongyloides stercoralis, is difficult to treat with drugs. The factors influencing this phenomenon remain unclear. To determine the host factors involved in response to treatment, 46 patients with strongyloidiasis were treated with albendazole, followed-up for 1 year, and separated into two groups: cured and non-cured. Serum levels of specific IgA, IgE, IgG, IgG1, and IgG4 antibodies were estimated using S. stercoralis antigen. Significantly higher titers of IgG4 antibody were observed in the non-cured group than in the cured group (P = 0.016). A total of 88 patients were typed for HLA-DRB1 alleles and analyzed for serum levels of antibody. The S. stercoralis-specific IgG4 antibody titers were significantly higher in the HLA-DRB1*0901-positive group than in the negative group (corrected P = 0.044). These results suggest that HLA-DRB1*0901 is a possible genetic marker for resistance to treatment of S. stercoralis that is associated with elevation of S. stercoralis-specific IgG4 antibody titer.
A case of fatal strongyloidiasis associated with human T-cell lymphotropic virus type 1 (HTLV-1) infection is described in a 45-year-old West Indian man living in an area endemic for both strongyloidiasis and HTLV-1 infection. Clinical presentation was typical with severe diarrhea, vomiting, and progressive weight loss. Stool microscopy revealed Strongyloides stercoralis rhabditiform larvae. Despite treatment with thiabendazole, the patient died. Autopsy findings revealed severe ileocolitis due to Strongyloides larvae, right subdiaphragmatic pyogenic abscess, and severe pleuritis of the right lower lobe of the lung. This case illustrates that despite effective antihelmintic therapy, mortality is still high in patients with the hyperinfective state of S. stercoralis. Thus, in patients in areas endemic for both Strongyloides infection and HTLV-1, or in immigrants from these areas, repeated stool microscopy is indicated in patients positive for HTLV-1.
INTRODUCTION: Strongyloidiasis is one of the major human intestinal infections caused by a minute nematode, Strongyloides stercoralis. It is a soil-transmitted nematode of worldwide distribution, which resides in the small intestines of humans and is acquired by tissue penetration by the infective stage, filariform larva, of the worm. In the immunocompetent hosts, Strongyloides stercoralis infects only the mucosal of the small intestines and persists as an asymptomatic often chronic infection. In contrast, in the presence of immune suppression it has ability to multiply within the human host, known as hyperinfection. Its occurrence has been reported more commonly among adults. AIM/OBJECTIVE: This study was undertaken to find the occurrence of Strongyloides stercoralis among children 0-5years who presented with diarrhea and then relate it to their nutritional status. MATERIALS AND METHOD: Following ethical approval, two hundred and twenty seven children, 118 boys and 109 girls, with complaints of diarrhoea, were randomly selected. A structured questionnaire was completed for each child. Anthropometric measurement was taken. Clinical assessment/diagnosis by the attending physician was also recorded. Stool specimen was collected and examined by wet preparation and formol-ether concentration methods. Infected children were treated. RESULTS: Twelve (5.3 %) of all the children with diarrhoea were found to have Strongyloides stercoralis. All the infected children were malnourished while none of the normal nourished children had Strongyloides stercoralis (p=0.001). CONCLUSION: Strongyloidiasis is a possible complication of Malnutrition in children who presented with diarrhoea.
The prevalence of antibodies against Strongyloides in the serum of newly-arrived Indochinese immigrants was determined. Sera that had been stored in the State Health Laboratories, Perth, were stratified according to age and sex, then samples were selected at random. Two hundred and ninety sera that had been obtained from persons between the ages of one and 69 years were examined by an indirect fluorescent antibody test. Five per cent of children who were aged between one and two years gave positive reactions. The positive reaction rate in this population increased by approximately 7% per year until the age of seven to eight years at which point it levelled off. Approximately half of all older children, teenagers and adults had positive antibody responses, indicating past or present infection with Strongyloides stercoralis. This parasite is an extremely unusual worm in that it is able to replicate within the human host. Consequently, infection may persist for years. Furthermore, immunosuppression may result in fatal, disseminated infection. Strongyloidiasis is now recognized in three major Australian population groups: Aborigines who are living in the north of the country; World War II veterans who were prisoners in southeast Asia; and Indochinese immigrants. The salient features of the clinical manifestations, diagnosis and treatment of strongyloidiasis are reviewed.
OBJECTIVE: To report the prevalence and distribution of infections with the parasitic nematode Strongyloides stercoralis in the Aboriginal and Torres Strait Islander communities of Queensland. DESIGN: A 20-year retrospective survey of computerised data and selected files from the former Aboriginal Health Programme (AHP) of the State Health Department of Queensland, based on cases diagnosed by the microscopic examination of preserved faecal specimens. Findings were compared with figures published in annual reports. STUDY POPULATION: Children under 15 years of age from 122 Aboriginal and Torres Strait Islander communities. RESULTS: Numbers of specimens examined varied widely according to time and place, as did detected infection rates. In 32,145 faecal samples examined by AHP microscopists during 1972-1991 the overall infection prevalence was 1.97%. Strongyloides larvae were found in only 52 of 122 communities. The parasite was absent from many small, southern inland communities, and the prevalence of infection increased in northern regions with summer wet seasons. On average, it was highest in Doomadgee (12%), where a peak prevalence of 27.5% (92/334 children examined) was detected in a wet season survey. Some infections resolved spontaneously, while others persisted for more than four years. At Gununa (Mornington Island), the prevalence fell from 26.2% to below 7% after thiabendazole treatment of most infected children, and remained at this level for at least four years. Single stool examinations by experienced microscopists may have failed to diagnose at least 26% of infected cases. The records give no indication of the clinical impact of strongyloidiasis. CONCLUSIONS: Strongyloidiasis is well established in many Aboriginal communities of north-eastern Australia. Children appear to be the major reservoirs of infection; the prevalence in adults is probably much lower. Failing improvements in community sanitation and hygiene, it may be possible to reduce significantly, if not eradicate, the infection by selectively treating diagnosed children with thiabendazole.